To be safe:
* Check your policy: Review your policy documents or contact your insurance company. They can tell you for sure how long you can keep your car in another state before it requires a change of address on your policy.
* Inform your insurer: If your vacation is unusually long, it's best to inform your insurer. This avoids potential issues if something happens while the car is in the other state. They may need to adjust your policy or rates.
In short, for a typical vacation, you likely don't need to change your insurance. But for extended stays, it's crucial to contact your insurance provider.